


MooseX::Role::PUsereContributed PeMooseX::Role::Parameterized(3p)


NAME
       MooseX::Role::Parameterized - roles with composition parameters

SYNOPSIS
           package Counter;
           use MooseX::Role::Parameterized;

           parameter name => (
               isa      => 'Str',
               required => 1,
           );

           role {
               my $p = shift;

               my $name = $p->name;

               has $name => (
                   is      => 'rw',
                   isa     => 'Int',
                   default => 0,
               );

               method "increment_$name" => sub {
                   my $self = shift;
                   $self->$name($self->$name + 1);
               };

               method "reset_$name" => sub {
                   my $self = shift;
                   $self->$name(0);
               };
           };

           package MyGame::Weapon;
           use Moose;

           with Counter => { name => 'enchantment' };

           package MyGame::Wand;
           use Moose;

           with Counter => { name => 'zapped' };

MooseX::Role::Parameterized::Tutorial
       Stop! If you're new here, please read
       MooseX::Role::Parameterized::Tutorial for a much gentler introduction.

DESCRIPTION
       Your parameterized role consists of two new things: parameter
       declarations and a "role" block.

       Parameters are declared using the "parameter" keyword which very much
       resembles "has" in Moose. You can use any option that "has" in Moose



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MooseX::Role::PUsereContributed PeMooseX::Role::Parameterized(3p)


       accepts. The default value for the "is" option is "ro" as that's a very
       common case. Use "is => 'bare'" if you want no accessor. These
       parameters will get their values when the consuming class (or role)
       uses "with" in Moose. A parameter object will be constructed with these
       values, and passed to the "role" block.

       The "role" block then uses the usual Moose::Role keywords to build up a
       role. You can shift off the parameter object to inspect what the
       consuming class provided as parameters. You use the parameters to
       customize your role however you wish.

       There are many possible implementations for parameterized roles
       (hopefully with a consistent enough API); I believe this to be the
       easiest and most flexible design. Coincidentally, Pugs originally had
       an eerily similar design.

       See MooseX::Role::Parameterized::Extending for some tips on how to
       extend this module.

   Why a parameters object?
       I've been asked several times "Why use a parameter object and not just
       a parameter hashref? That would eliminate the need to explicitly
       declare your parameters."

       The benefits of using an object are similar to the benefits of using
       Moose. You get an easy way to specify lazy defaults, type constraint,
       delegation, and so on. You get to use MooseX modules.

       You also get the usual introspective and intercessory abilities that
       come standard with the metaobject protocol. Ambitious users should be
       able to add traits to the parameters metaclass to further customize
       behavior. Please let me know if you're doing anything viciously
       complicated with this extension. :)

CAVEATS
       You must use this syntax to declare methods in the role block: "method
       NAME => sub { ... };". This is due to a limitation in Perl. In return
       though you can use parameters in your methods!

       "alias" in Moose::Role and "excludes" in Moose::Role are not yet
       supported. I'm completely unsure of whether they should be handled by
       this module. Until we figure out a plan, either declaring or providing
       a parameter named "alias" or "excludes" is an error.

AUTHOR
       Shawn M Moore, "sartak@gmail.com"

SEE ALSO
       http://sartak.blogspot.com/2009/05/parameterized-roles.html
       <http://sartak.blogspot.com/2009/05/parameterized-roles.html>

       http://stevan-little.blogspot.com/2009/07/thoughts-on-parameterized-roles.html
       <http://stevan-little.blogspot.com/2009/07/thoughts-on-parameterized-
       roles.html>



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MooseX::Role::PUsereContributed PeMooseX::Role::Parameterized(3p)


       http://sartak.org/talks/yapc-asia-2009/(parameterized)-roles/
       <http://sartak.org/talks/yapc-asia-2009/(parameterized)-roles/>

       <http://perldition.org/articles/Parameterized%20Roles%20with%20MooseX::Declare.pod>

COPYRIGHT AND LICENSE
       Copyright 2007-2010 Infinity Interactive

       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.















































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